Rotary sieving apparatus



18, 1964 GENICHI YOSHIKAWA 3,144,939

ROTARY SIEVING APPARATUS Filed July 5, 1961 FIG. 4

INVENTOR Gen/chi Yoshikawa ATIORNEY 4 WWMMZ/M' United States Patent C) 3,1d4,939 ROTARY SlEVlP-IG APPARATU?) Genichi Yoshikawa, Yawata, Eapan, assignor to Yawata Iron and Steel Co., Ltd, Tokyo, Japan, a corporation of Japan Filed duly 5, 1961, Ser. No. 121,913 Claims priority, application, Japan, July 6, 19%, 35/3il,71l5 3 Claims. (Cl. 2ii995) This invention relates to a cylindrical rotary sieving apparatus or more particularly to a sieving apparatus for such solids as scrap iron.

In dividing the sizes of solids, such sieving apparatuses as of square meshes or rod screens have been generally used. However, the shapes of such solids as scrap iron are not constant but are so varied that, with the conventional sieving apparatus, the meshes will be clogged and the sieving operation will be difiicult.

As well known, in the iron manufacturing industry, scrap iron is very valuable as one of the important raw materials. However, when scrap iron is to be used, it will have to be sorted. Especially, the sorting of scrap iron according to the shapes and dimensions is a factor very important to the improvement of the operating efiiciency for the subsequent scrap iron treatment. But there has been no proper apparatus for such sorting treatment.

As a result of carrying on researches on the automatic sorting of scrap iron according to the shapes and dimensions of scrap iron from such viewpoint, I have completed the present invention which is new as entirely different in the inventive idea from any conventional sorting apparatus.

That is to say, I have come to know that, when a rotary cylindrical kiln is properly inclined, a material to be treated is thrown into the kiln and the kiln is rotated, it will be possible to sort the material into a portion of small shapes and dimensions and a portion of large ones due to the action of the centrifugal force by such rotation and further that, when several rails are laid spirally on the inside of the above described kiln and the above mentioned sorting is carried out, only the portion of large shapes and dimensions will slide on the rails, the portion of small shapes and dimension will slide on the inside wall of the kiln and the large and small shape portions will be able to be easily sorted from each other.

That is to say, an object of the present invention is to provide an apparatus for automatically and continuously sorting such solids as, for example, scrap iron by using a rotary cylindrical kiln.

Another object of the present invention is to provide an apparatus for sorting such solids as, for example, scrap iron according to the shapes and dimensions by using a rotary cylindrical kiln.

Other objects of the present invention will be understood from the following detailed explanation and accompanying drawings.

The drawings shall be explained.

FIGURE 1 is an elevation of a rotary sieving apparatus according to the present invention.

FIGURE 2 is a side view on line A-A in FIGURE 1.

FIGURE 3 is an explanatory view showing the shapes of the rails in the rotary sieving apparatus according to the present invention.

FIGURE 4 is an explanatory view of the cylinder of the rotary sieving apparatus according to the present invention.

The present invention relates to a rotary sieving apparatus wherein a plurality of spiral rails of a coarse pitch are laid on the inside of a cylindrical kiln rotating while ice keeping a proper inclination and are extended at the respective ends out of the cylinder as they are.

Therefore, according to the present invention, when scrap iron moves toward a discharging port along the rails due to the rotation of the cylindrical kiln, a portion of comparatively small shapes will move toward the discharging port along the cylinder wall between the rails and will drop down from the end of the cylinder and a portion or large shapes will slide on the rails, will move toward the discharging port and will drop down from the ends of the rails so that the large shape portion and small shape portion of the scrap iron may be sorted and separated respectively at the end part of the rails and at the end part of the cylinder.

That is to say, in the present invention, as described above, as the several spiral rails laid within the cylindrical kiln are extended and projected spirally from the end part of the kiln, the portion of large shapes and dimensions will slide on said rails and will drop down at a point far from the end of the kiln but the small material treated Will not be able to slide on the rails, will therefore slide on the wall of the kiln and will, as a result, drop down from the end of the kiln.

When the cylindrical kiln is provided with a zone of proper small holes in the end part as required, fine scales and the like will be able to be dropped down through the small holes and therefore the sorted kinds will be able to be finely divided.

The shape of the rails laid inside the cylinder need not be specified. However, preferably, if 2 to 8 rails of a triangular shape properly rounded at apex are laid, the flow of the material to be treated will be able to be made easy. According to my finding, the internally laid rails of an equilateral triangle properly rounded at the apex can be used in a standard sieving machine. If a scalene triangle properly rounded at the apex is used, there will be advantages that the flow of the raw material will be made easy and that long things will be more easily arranged in parallel with the axis of the cylinder. The angle of said apex is determined by the size of the cylinder and the number of the rails but is found by experiments to be preferably 30 to degrees.

Further, the height of the rail depends on the shape and feed of the raw material and the rotating speed but is actually less than 660 mm. and preferably to 200 mm.

The number of the spiral rails has much to do With the attainment of the objects of the present invention. In the case of bar-shaped long things, even if the spiral rails are few, the objects will be able to be attained. But, in the case of blocks, it will be desirable to increase the rails. According to my finding, 2 to 8 rails are most effective.

Further, in order to improve the sieving efficiency, the axis of the flow of the raw material due to the rotation and the axis of the cylinder may be made parallel with each other. For this purpose, the number of spirals is so determined that the material to be treated may slide from the top of the rail to the top of the next rail.

In order to sort the material into many kinds of shapes and dimensions, if the cylinder is provided, for example, with a zone of medium holes for dropping small things or a zone of small holes for dropping scales adjacent thereto as described above, the sorting efficiency will be able to be improved.

As regards the sizes of the holes, the zone of medium holes is provided in the part near the end and the zone of small holes is made adjacent to it. In industrially working the present invention, in order to prevent the recovered small things and scales from dying out through the medium and small hole zones, it is desirable to make the medium and small hole zones double cylinders and to 3 set respective recovering hoppers in the inclined end parts.

The number of revolutions of the cylinder is not specifically limited. It may be determined in response to the shape of the material to be treated and the amount of the charge but is preferably made 6 to 15 rpm. The angle of inclination of the cylinder is not specifically limited but is preferably made 10 to 20 degrees.

The present invention shall now be explained with reference to an embodiment illustrated in the drawings.

Several spiral rails of a coarse pitch made of an inverted V-shaped steel member are laid on the inside of a cylinder 1 and are extended as they are at the ends out of the cylinder by a proper length. Wheels 2 and a gear 3 are provided in both end parts and a part outside the cylinder 1. Foundations 4.- and 4' are so provided that said cylinder 1 may incline. The wheel part 2 is supported by a grooved pulley 7 borne by a bearing 6 fixed on the foundation 4 or 4. The wheel part 2 is supported on the side by a supporting pulley 8. The gear 10 of a motor 9 is meshed with the gear 3 outside the cylinder so that the cylinder It may be rotated. A chute 11 is provided at one end.

Therefore, the scrap iron fed through the chute 11 will move toward the discharging port along the rails 5 due to the inclination and rotation of the cylinder 1. In such case, comparatively small things will move toward the discharging port along the cylinder wall between the rails and will drop down from the end of the cylinder 1 and the large things will slide on the rails 5, will move toward the discharging port and will drop down from the ends of the rails 5. Therefore, the distance between the position in which the large things drop and the position in which the small things drop can be distinguished by the ends of the rails and the end of the cylinder. Thus, there is an advantage that the large things and small things can be easily respectively divided.

FEGURE 3 shows an example of laying the rails inside the cylinder of the rotary sieving apparatus of the present invention. The rails are spirally laid on the inside wall of the cylinder from a proper position in the material charging port and are extended and projected spirally as they are at the ends by a proper length from the material discharging port of the cylinder.

The shape of the rail is shown to be triangular in FIG- URE 3 but may be also semicircular, it being desirable to provide between the successive rails a space which diverges inwardly toward the axis of the cylindrical body l. The provision of such an inwardly diverging space permits the scrap iron being sorted to move along the cylindrical body without becoming jammed in the spaces between the successive rails.

If the cylinder 1 is provided with a medium hole zone 13 and a small hole zone 14 in proper places in the cylinder 1 as shown in FIGURE 4, small things of scrap iron will be recovered from the medium hole zone and scales and other fine things will be recovered from the small hole zone. When these hole zones are covered with double cylinders, the small things and fine things of the treated material discharged through said holes 13 and 114, respectively, will be able to be recovered in the respective hoppers as adapted to the practice.

Example I succeeded in get-ting eificient sorting with a preferable embodiment of the sieving apparatus of the present invention wherein the length of the cylinder was 7.4 m., the inside diameter of the cylinder was 2 m., the pitch of the spiral was 450 mm., the clearance of the spirals was 250 mm., the height of the rail was mm., the length of the projection of the spiral rails out of the cylinder was 1,400 mm., the diameter of the medium hole was 150 mm., the diameter of the small hole was 18 mm., the inclination of the apparatus was 15 degrees and the number of revolutions was 10 rpm.

This is to say, large things of the scrap iron could be sorted in the end part of the spiral rails and medium things thereof in the end part of the cylindrical kiln and small things could be sorted and recovered from the medium hole zone and scales from the small hole Zone.

The treated amount was 45 to 50 tons/hr.

What I claim is:

1. A rotary sorting and sieving apparatus for scrap iron comprising a hollow cylindrical body having the longitudinal axis thereof inclined to the horizontal and having an intake opening at the upper end of said cylindrical body and a discharge opening at the lower end of said cylindrical body, rotating means on which said cylindrical body is mounted for rotating about said inclined longitudinal axis, and a plurality of from 2 to 8 rails on the inside of said cylindrical body extending spirally along the inside surface of said cylindrical body at a coarse pitch from said intake opening and projecting out of the discharge opening beyond the end of said cylindrical body, said rails having a cross section with the maximum dimension at the inside surface of the hollow cylindrical body and having a progressively decreasing dimension in the direction toward the axis of the cylindrical body for providing between the successive rails 21 space diverging inwardly toward the axis of the cylindrical body, said rails having a radial dimension of from 150 mm. to 600 mm. and the cylindrical body having an inside diameter on the order of two meters, whereby scrap iron is automatically sorted as it is moved along the cylindrical body without jamming in the diverging spaces between the successive rails and large pieces are carried beyond the discharge end of the cylindrical body while smaller pieces fall out of the end of the cylindrical body.

2. A rotary sieving apparatus as claimed in claim 1 in which the cross-section of said rails is triangular and no greater than 200 mm. in radial dimension.

3. A rotary sieving apparatus as claimed in claim 1 in which the cross-section of said rails is semicircular and no greater than 200 mm. in radial dimension.

References Cited in the file of this patent UNITED STATES PATENTS 504,186 Wilson Aug. 20, 1893 958,565 Torjusen et al. May 17, 1910 1,140,700 Michaelsen May 25, 1915 1,693,001 Smith Nov. 27, 1928 1,809,586 Evans June 9, 1931 FOREIGN PATENTS 23,515 Great Britain Oct. 11, 1910 771,016 France July 16, 1934 794,728 France Dec. 26, 1935 800,162 France Apr. 20, 1936 UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No, 3,144,939 August 18, 1964 Genichi Yoshikawa It is hereby certified that error appears in the above numbered patent requiring correction and that the said Letters Patent should read as corrected below.

In the grant, lines 1 to 3, for "Genichi Yoshikawa, of Yawata, Japan, assignor to Yawata Iron and Steel Co, Ltd, of

Tokyo, Japan, a corporation Japan," read Genichi Yoshikawa, of Yawata, Japan, assignor of one-half to Yawata Iron amifiir eel C0. Ltd. of Tokyo, Japan, a corporation of Japan, line 12,

for "Yawata Iron and Steel Co. Ltd, its successors" read "Genichi Yoshikawa, his heirs or assigns and Yawata Iron and Steel Co, Ltd. its successors in the heading to the printed specification, lines 3 to 5, for "Genichi Yoshikawa, Yawata, Japan, assignor to Yawata Iron and Steel Co. Ltd Tokyo,

Japan, a corporation of Japan" read Genichi Yoshikawa,

Yawata, Japan, assignor of one-half to Yawata Iron and Steel Co, Ltd. Tokyo, Japan, a corporation of Japan Signed and sealed this 13th day of April 1965,

(SEAL) Attest:

ERNEST W, SWIDER EDWARD J. BRENNER Attesting Officer Commissioner of Patents 

1. A ROTARY SORTING AND SIEVING APPARATUS FOR SCRAP IRON COMPRISING A HOLLOW CYLINDRICAL BODY HAVING THE LONGITUDINAL AXIS THEREOF INCLINED TO THE HORIZONTAL AND HAVING AN INTAKE OPENING AT THE UPPER END OF SAID CYLINDRICAL BODY AND A DISCHARGE OPENING AT THE LOWER END OF SAID CYLINDRICAL BODY, ROTATING MEANS ON WHICH SAID CYLINDRICAL BODY IS MOUNTED FOR ROTATING ABOUT SAID INCLINED LONGITUDINAL AXIS, AND A PLURALITY OF FROM 2 TO 8 RAILS ON THE INSIDE OF SAID CYLINDRICAL BODY EXTENDING SPIRALLY ALONG THE INSIDE SURFACE OF SAID CYLINDRICAL BODY AT A COARSE PITCH FROM SAID INTAKE OPENING AND PROJECTING OUT OF THE DISCHARGE OPENING BEYOND THE END OF SAID CYLINDRICAL BODY, SAID RAILS HAVING A CROSS SECTION WITH THE MAXIMUM DIMENSION AT THE INSIDE SURFACE OF THE HOLLOW CYLINDRICAL BODY AND HAVING A PROGRESSIVELY DECREASING DIMENSION IN THE DIRECTION TOWARD THE AXIS OF THE CYLINDRICAL BODY FOR PROVIDING BETWEEN THE SUCCESSIVE RAILS A SPACE DIVERGING INWARDLY TOWARD THE AXIS OF THE CYLINDRICAL BODY, SAID RAILS HAVING A RADIAL DIMENSION OF FROM 150 MM. TO 600 MM. AND THE CYLINDRICAL BODY HAVING AN INSIDE DIAMETER ON THE ORDER OF TWO METERS, WHEREBY SCRAP IRON IS AUTOMATICALLY SORTED AS IT IS MOVED ALONG THE CYLINDRICAL BODY WITHOUT JAMMING IN THE DIVERGING SPACES BETWEEN THE SUCCESSIVE RAILS AND LARGE PIECES ARE CARRIED BEYOND THE DISCHARGE END OF THE CYLINDRICAL BODY WHILE SMALLER PIECES FALL OUT OF THE END OF THE CYLINDRICAL BODY. 